As a new United Nations report warned global temperature rise  within the next few years, pushing climate risks and impacts to increasingly dangerous heights, campaigners say it does not go anywhere near far enough.

The UN Environment Programme (UNEP) report says while crossing the threshold is now irreversible it is still possible to bring temperatures down and achieve global goals in the Paris Agreement,

The report, Limiting Overshoot, identifies an ‘overshoot, peak, and decline’ pathway as the best remaining option to minimize the magnitude and duration of this overshoot and try to return to below 1.5°C as soon as possible.

“This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead. We must make the overshoot above 1.5 degrees as small and short as possible. That demands an overshoot of ambition” said UN secretary-general Antőnio Guterres. (pic)

This pathway would minimise peak temperature rise through immediate and sustained cuts to greenhouse gas emissions, including methane, on the road to net-zero, and bring down temperatures through long-term net-negative emissions, with carefully governed Carbon Dioxide Removal (CDR) – the process of removing carbon from the air and storing it through afforestation or other means – an essential part of the mix.

At the same time, following this pathway would involve adaptation actions that reduce vulnerability to the current, expected and unexpected impacts of climate change on societies, communities and economies – although there will likely be limits to adaptation and irreversible impacts, especially if peak temperatures are not minimized. The report stresses such a pathway would reduce risks and impacts, make adaptation less difficult and expensive, and increase the chances of lowering temperatures.

“There are no good outcomes if we remain above 1.5°C. Across the globe, extreme heatwaves are already proving that climate impacts will strike faster, hit harder, and last longer – costing more lives and causing deeper disruption,” said Inger Andersen, Executive Director of UNEP. “Now is the time we must double down on climate action. We can – and must – get on the right path. By cutting greenhouse gas emissions, strengthening resilience and adaptation, and ensuring exceedance of 1.5°C is as small and short as possible.”

The most optimistic scenario will see temperature rise peak at 1.8°C above pre-industrial levels, above the goal of limiting warming to 1.5°C set by the Paris Agreement. Most other scenarios predict higher peaks.

Above 1.5°C, risks and impacts will intensify with every extra fraction of a degree and every year. Anticipated impacts include intensified extreme weather, ecosystem loss, and submersion of Small Island Developing States and low-lying coastal cities. Severe damage to human health, food security, water supplies, nature, cities, infrastructure, and economies is expected.

The report warns that the likelihood of crossing irreversible tipping points increases with the magnitude and duration of higher temperatures. These include the destabilization of major ice sheets, degradation of the Amazon rainforest and disruption of the Atlantic Meridional Overturning Circulation (the system of currents that moves warm surface water north and cold deep water south, playing a key role in regulating the climate). Some impacts may emerge abruptly, while others will accumulate over time.

“Considering the scale of the risks and the co-benefits of climate interventions such as a rapid transition away from fossil fuels to renewable energy – improving air quality and public health, lowering energy costs and increasing access to electricity,”  the report added.

UNEP has urged accelerated, collective and global action to get on an overshoot, peak and decline pathway. How quickly and strongly this action happens will define the shape and trajectory of the pathway.

“This report is a reminder that an overshoot, peak and decline pathway is a next generation climate frontier, but one which cannot be left unattended to for the next generation to tackle. Immediate action is required for such a pathway to remain possible,” UNEP added.

However, campaigners at Climate Analytics, said the report is big on words but short on action,

It said: “Originally scheduled for release in June, the UNEP report is based on science showing that due to governments’ repeated failure to cut greenhouse gas emissions in line with the Paris Agreement, it is now inevitable that the 1.5°C global warming limit agreed in Paris will be breached, taking the world into ‘climate overshoot.’ “

‘As UNEP sets out very clearly, overshooting the 1.5°C limit will make life difficult on many fronts,’ said Bill Hare, CEO of Climate Analytics and a former lead author on Intergovernmental Panel on Climate Change (IPCC) assessments.  ‘It will exacerbate climate impacts, especially in the least developed countries and small island developing states – it will increase the number of impacts that are beyond our capacity to adapt to, and will increase the risk of major tipping points such as irreversible ice-sheet melt or rainforest die-off.

‘However, although UNEP does a good job of describing the hole we’ve dug ourselves into, it does a poor job of showing us that there is a way out, and ultimately the report’s neglect of some fundamentally important mitigation analysis risks turning it into a call to apathy rather than a call to arms.’

“Transformational adaptation is distinct from the urgent and growing need to address present and future losses and damages,” said Dr Rosanne Martyr, Climate Analytics’ scientific group lead for Adaptation and Loss and Damage. “Responses to profound losses such as uninhabitability or permanent submersion of land will need to be systemic, equitable and just. Transformational adaptation has to be just one component of a coherent and just response to escalating impacts, which must also encompass urgent reduction of emissions by countries most responsible and redress for losses and damages.”